Drug interactions
Diphenhydramine + Ethanol
Severity: Moderate
Diphenhydramine and Ethanol: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Alcohol and diphenhydramine both depress the central nervous system, leading to marked drowsiness, impaired judgement, slowed reaction time and poorer driving performance. Higher alcohol intake may produce profound sedation.
What this interaction means in plain words
Diphenhydramine and Ethanol can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Additive CNS depression from alcohol's GABAergic effects and H1 antagonism in the brain.
What to do
Advise patients to avoid alcohol while taking diphenhydramine. Warn against driving or operating machinery.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Diphenhydramine and Ethanol, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Ethanol?
MediHelp rates the interaction as moderate. Diphenhydramine and Ethanol can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Alcohol and diphenhydramine both depress the central nervous system, leading to marked drowsiness, impaired judgement, slowed reaction time and poorer driving performance. Higher alcohol intake may produce profound sedation.
How serious is the interaction between Diphenhydramine and Ethanol?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to avoid alcohol while taking diphenhydramine. Warn against driving or operating machinery.
What other medicines interact with Diphenhydramine?
MediHelp also lists interactions of Diphenhydramine with, for example, Alfentanil, Belladonna and opium, Benzhydrocodone / acetaminophen. The full list is on the Diphenhydramine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
